抄録
The surface of dental implants are designed to achieve implant stabilization and initial anchorage in bone, and also the surface topography influences the differentiation and other characteristics of cultured cells. There have been many investigations on the effects of surface topography on osteogenetic cells, but few on comparable effects with respect to osteoclasts and/or giant cells in vitro. The behavior of osteoclast-like cells cultured on commercially pure titanium with differing surface rugosities was investigated.
Commercially pure titanium plates were produced with 4 different degrees of surface rugosity: 1) Polished grade (ave.0.25 μm), 2) Untreated grade (ave.1.75 μm), 3) Fine sandblasted grade (ave.8 μm) and 4) Rough sandblasted grade (ave.23.2 μm). Primary rat bone marrow (RBM) cells were obtained and cultured using the method of Maniatopoulos et al. Aliquots of 100 μl of cell suspension were distributed in corresponding sequence for each group. On the following day,1.5 ml of the same medium was added to each well, and the cultures were maintained for 7 days being fed 3 times a week. After fixation, these samples were stained for TRAP. Light microscopy was used to examine the changes in cell morphology of these samples and to quantify the multinucleate giant cells. On the polished plates, small round cells were mainly observed. In contrast, multinucleated giant cells with spreading cell processes were seen on the roughened substrata. The number of multinucleated giant cells was 117.0 ±20.5 cells/plate on the polished plates, 271.1±53.9 cells/plate on the untreated plates, 357.1±96.6 cells/plate on the fine sandblasted plates and 314.8±96.2 cells/plate on the rough sandblasted plates. Significant differences were found between the polished plates and the others.
These results indicated that on the roughened substrata, compared to the polished substrata, there is increased differentiation of multinucleated osteoclast-like giant cells from bone marrow precursor cells obtained from the same femur source. This confirms our previous report that the number of multinucleated TRAP positive cells is significantly higher on the roughened hydroxyapatite substrata than that on the smooth substrata.
Surface topography, especially material microstructure, can influence cell morphology, behavior, differentiation and other characteristics. Therefore cellular response to implant surface topography is an important area of investigation in the pursuit of improvement in implant stability and prognosis.
